Anti-acne cosmetic compositions

ABSTRACT

An anti-acne cosmetic composition in the form of a multiple phase water-in-oil emulsion and process for preparing thereof, wherein the composition comprises two or more aqueous phases and a coalescence inhibitor for preventing coalescence of the aqueous phases and wherein at least a first aqueous phase comprises the anti-acne active in the form of an aqueous/alcoholic solution. The composition exhibits moisturisation, anti-acne activityand skin anti-ageing benefits, together with product and colour stability.

This application is a 371 of PCT/US95/10135 filed Aug. 8, 1995.

TECHNICAL FIELD

The present invention relates to cosmetic compositions. In particular itrelates to tinted cosmetic compositions which provide excellentmoisturisation, together with improved anti-acne activity and skinanti-ageing benefits and formulation and colour stability.

BACKGROUND OF THE INVENTION

Skin is made up of several layers of cells which coat and protect thekeratin and collagen fibrous proteins that form the skeleton of itsstructure. The outermost of these layers, referred to as the stratumcorneum, is known to be composed of 250 Å protein bundles surrounded by80 Å thick layers. Anionic surfactants and organic solvents typicallypenetrate the stratum corneum membrane and, by delipidization (i.e.removal of the lipids from the stratum corneum), destroy its integrity.This destruction of the skin surface topography leads to a rough feeland may eventually permit the surfactant or solvent to interact with thekeratin, creating irritation.

It is now recognised that maintaining the proper water gradient acrossthe statum corneum is important to its functionality. Most of thiswater, which is sometimes considered to be the stratum corneum'splasticizer, comes from inside the body. If the humidity is too low,such as in a cold climate, insufficient water remains in the outerlayers of the stratum corneum to properly plasticize the tissue; and theskin begins to scale and becomes itchy. Skin permeability is alsodecreased somewhat when there is inadequate water across the stratumcorneum. On the other hand, too much water on the outside of the skincauses the stratum corneum to ultimately sorb three to five times itsown weight of bound water. This swells and puckers the skin and resultsin approximately a two to three fold increase in the permeability of theskin to water and other polar molecules.

Thus, a need exists for compositions which will assist the stratumcorneum in maintaining its barrier and water retention functions atoptimum performance in spite of deleterious interactions which the skinmay encounter in washing, work, and recreation.

Conventional cosmetic cream and lotion compositions as described, forexample, in Sagarin, Cosmetics Science and Technology, 2nd Edition, Vol.1, Wiley Interscience (1972) and Encyclopaedia of Chemical Technology,Third Edition, Volume 7 are known to provide varying degrees ofemolliency, barrier and water-retention (moisturising) benefits.However, they can also suffer serious negatives in terms of skin feel(i.e. they often feel very greasy on the skin) as well as having poorrub-in, absorption and residue characteristics.

It would also be desirable to provide a cosmetic composition whichdelivered pigments to the skin of the user at the same time as providingexcellent moisturisation. A pigmented cosmetic composition can serve toeven skin tone and texture and to hide pores, imperfections, fine linesand the like.

At the same time, it would be desirable to provide a moisturisingcomposition having topical anti-acne activity. There are many compoundswhich are known to exhibit anti-acne properties when applied topicallyto the skin. A commonly used keratolytic agent having anti-acne activityis salicylic acid. As salicylic acid is virtually insoluble in waterhowever, it is difficult to incorporate into the aqueous phase of anemulsion composition. Delivery of salicylic acid from thepigment-containing oil phase of an emulsion composition can, on theother hand, lead to discolouration of the composition due to interactionbetween the salicylic acid and pigments, especially of the iron oxidetype. Furthermore, in compositions requiring high water levels, such asskin moisturising compositions, salicylic acid tends to precipitate outof solution. It would therefore be desirable to deliver salicylic acidin soluble form from the aqueous phase but without the salicylic acidprecipitating out of solution.

It is accordingly one object of the present invention to provide acosmetic composition which exhibits anti-acne activity together withmoisturisation benefits.

It is a further object of the invention to provide a cosmeticcomposition in the form of a multiple phase emulsion having improvedproduct and colour stability.

SUMMARY OF THE INVENTION

According to one aspect of the present invention there is provided ananti-acne cosmetic composition in the form of a multiple phasewater-in-oil emulsion, wherein the composition comprises:

(a) two or more aqueous phases; and

(b) a coalescence inhibitor for preventing coalescence of the aqueousphases;

and wherein at least a first aqueous phase comprises an anti-acne activein the form of an aqueous/alcoholic solution.

According to the present invention there is also provided a process forpreparing an anti-acne composition, the process comprising the steps of:

(a) preparing the first aqueous phase by dissolving the anti-acne activein an aqueous/alcoholic solution;

(b) admixing the first aqueous phase with the oil phase; and

(c) subsequently adding one or more additional aqueous phase or phasesto the resulting mixture to form the multiple phase water-in-oilemulsion, the first and/or additional aqueous phase or phases havingdissolved therein the coalescence inhibitor.

The compositions of the present invention provide anti-acne activity andskin anti-ageing benefits, together with improved product and colourstability and superior moisturisation, skin feel and appearance.

All levels and ratios are by weight of total composition, unlessotherwise indicated.

DETAILED DESCRIPTION OF THE INVENTION

The compositions of the present invention are multiple phasewater-in-oil emulsions which comprise two or more aqueous phases. Atleast a first aqueous phase comprises an anti-acne active in the form ofan aqueous/alcoholic solution. Suitable anti-acne actives for use hereininclude salicylic acid, retinoic acid, azelaic acid, lactic acid,glycolic acid, pyruvic acid, flavonoids, and derivatives and saltsthereof, and mixtures thereof.

The anti-acne active used in the composition herein is preferablyselected from salicylic acid and azelaic acid, and mixtures thereof,more preferably salicylic acid. The anti-acne active is present at alevel of from about 0.1% to about 10%, preferably from about 0.1% toabout 5%, more preferably from about 0.5% to about 3%, by weight ofcomposition.

The anti-acne active is solubilized in water or an alcoholic solution,for example, solutions based upon C₂ -C₆ alcohols, diols and polyols,preferred alcohols being selected from ethanol, dipropylene glycol,butylene glycol, hexylene glycol, and mixtures thereof. Alcohol ispreferably present in the compositions herein at a level of from about1% to about 20%. The final aqueous/alcoholic anti-acne active solutionpreferably has a pH at ambient temperature (25° C.) of less than aboutpK_(a) +1, where pK_(a) is the logarithmic acidity constant for thefully protonated anti-acne active. In preferred embodiments, the pH ofthe final solution is less than about pK_(a).

The logarithmic acidity constant is thus defined by reference to theequilibrium

    H.sup.+ +H.sub.n-1 A=H.sub.n A

where H_(n) A is the fully protonated acid, n is the number of protonsin the fully protonated acid and H_(n-1) A is the conjugate base of theacid corresponding to loss of one proton.

The acidity constant (Kn) for this equilibrium is therefore ##STR1##

    and pK.sub.a =log.sub.10 K.sub.n

For the purposes of this specification, acidity constants are defined at25° C. and at zero ionic strength. Literature values are taken wherepossible (see Stability Constants of Metal-Ion Complexes, SpecialPublication No. 25, The Chemical Society, London); where doubt arisesthey are determined by potentiometric titration using a glass electrode.

The pK_(a) of the acidic anti-acne active used herein is preferably inthe range of from about 1 to about 6, more preferably from about 1 toabout 4.5, especially from about 1.5 to about 4.0.

The pH of the final aqueous/alcoholic anti-acne active solution ispreferably in the range of from about 1 to about 7, more preferably fromabout 2 to about 5, especially from about 2 to about 4. At pH values ofless than about 5 the aqueous phase is preferably free of acid labilespecies such as acrylic acid/ethyl acrylate copolymers andpolyglycerylmethacrylate.

Another essential component of the compositions herein is a coalescenceinhibitor for preventing coalescence of the aqueous phases. Preferablythe coalescence inhibitor is an electrolyte or mixture of electrolytes,preferably sodium chloride. The coalescence inhibitor is present at alevel of from about 0.05% to about 5%, preferably from about 0.01% toabout 2% by weight of composition.

The compositions of the invention are in the form of a multiple phasewater-in-oil emulsion comprising two or more aqueous phases As mentionedhereinabove the compositions of the invention comprise at least a firstaqueous phase which comprises an anti-acne active in the form of anaqueous/alcoholic solution. This first aqueous phase preferablycomprises no more than about 20% by weight of water. The compositions ofthe invention also comprise a second aqueous phase which preferablycomprises at least about 15% by weight of composition of water.Preferably the compositions of the invention comprise in total fromabout 30% to about 50% by weight of water and about 1% to about 15% byweight of alcoholic solvent. The compositions herein will generallycomprise anti-acne active in an amount exceeding its solubility in anequivalent mixture of water and solvent measured under ambientconditions (25° C.). It is a feature of the invention however that byvirtue of the multiple phase form of the composition and the use of acoalescence inhibitor as described herein, the anti-acne material can beformulated in soluble form at levels exceeding its normal solubility ina single phase water/alcohol system.

Preferably the compositions of the invention comprise apyrrolidone-based complexing agent. The pyrrolidone-based complexingagent is useful herein from the viewpoint of aiding solubilization ofthe anti-acne active and also an interfacial film former for the aqueousphases for preventing coalescence of the aqueous phases. Thepyrrolidone-based complexing agent used herein is preferably selectedfrom polyvinylpyrrolidone complexing agents or C₁ -C₄ alkylpolyvinylpyrrolidone complexing agents having a molecular weight(viscosity average) in the range from about 1500 to about 1,500,000,preferably from about 3000 to about 700,000, more preferably from about5000 to about 100,000. Suitable examples of pyrrolidone-based complexingagents are polyvinylpyrrolidone (PVP) (or povidone) and butylatedpolyvinylpyrrolidone. The most preferred pyrrolidone-based complexingagent herein is a polyvinylpyrrolidone complexing agent. PVP iscommercially available under the trade name Luviskol (RTM) from BASF. Apreferred PVP complexing agent herein is Luviskol K17 which has aviscosity-average molecular weight of about 9,000. Otherpyrrolidone-based complexing agents for use herein include C₁ -C₁₈ alkylor hydroxyalkyl pyrrolidones such as lauryl pyrrolidone.

The pyrrolidone-based complexing agent is present in the compositionherein in a level of from about 0.1% to about 10%, preferably from about0.1% to about 5% by weight of composition. The weight ratio of anti-acneactive:pyrrolidone-based complexing agent is in the range from about10:1 to about 1:10, preferably from about 5:1 to about 1:5.

Preferred embodiments of the invention additionally comprise from about0.01% to about 5%, preferably from about 0.1% to about 1%, especiallyfrom about 0.1% to about 0.5% by weight of an acid or salt thereof whichis soluble in water at pH values of less than or equal to the pK_(a) ofthe corresponding acid, for example, an acid selected from citric acid,boric acid, and salts, and mixtures thereof. These materials arevaluable herein in combination with the pyrrolidone-based complexingagent from the viewpoint of aiding solubilization of the anti-acneactive. Particularly preferred herein from this viewpoint is a sodiumsalt of citric acid. In preferred embodiments, the acid or salt thereofis soluble to a level of at least 5% w/w at 25° C.

The composition of the invention is in the form of a multiple phasewater-in-oil emulsion containing two or more, preferably two discreteinternal aqueous phases. In preferred embodiments the oil phasecomprises a mixture of volatile silicones and non-volatile silicones.The silicone oil is present in an amount of from about 1% to about 50%by weight. Suitable volatile silicone oils include cyclic and linearvolatile polyorganosiloxanes (as used herein, "volatile" refers to thosematerials which have a measurable vapour pressure at ambientconditions).

A description of various volatile silicones is found in Todd, et al."Volatile Silicone Fluids for Cosmetics", 91 Cosmetics and Toiletries27-32 (1976).

Preferred cyclic silicones include polydimethylsiloxanes containing fromabout 3 to about 9 silicon atoms, preferably containing from about 4 toabout 5 silicon atoms. Preferred linear silicone oils include thepolydimethylsiloxanes containing from about 3 to about 9 silicon atoms.The linear volatile silicones generally have viscosities of less thanabout 5 centistokes at 25° C., while the cyclic materials haveviscosities of less than about 10 centistokes. Examples of silicone oilsuseful in the present invention include: Dow Corning 344, Dow Corning21330, Dow Corning 345, and Dow Corning 200 (manufactured by the DowCorning Corporation): Silicone 7207 and Silicone 7158 (manufactured bythe Union Carbide Corporation). SF:202 (manufactured by GeneralElectric) and SWS-03314 (manufactured by Stauffer Chemical).

Suitable non-volatile silicones preferably have an average viscosity offrom about 1,000 to about 2,000,000 mm².s⁻¹ at 25° C. more preferablyfrom about 10,000 to about 1,800,000 mm².s⁻¹, even more preferably fromabout 100,000 to about 1,500,000 mm².s⁻¹. Lower viscosity non-volatilesilicone conditioning agents, however, can also be used. Viscosity canbe measured by means of a glass capillary viscometer as set forth in DowCorning Corporate Test Method CTM0004, Jul. 20, 1970. Suitablenon-volatile silicone fluids for use herein include polyalkyl siloxanes,polyaryl siloxanes, polyalkylaryl siloxanes, polysiloxanes with aminofunctional substitutions, polyether siloxane copolymers, and mixturesthereof. The siloxanes useful in the present invention may be endcappedwith any number of moieties, including, for example, methyl, hydroxyl,ethylene oxide, propylene oxide, amino and carboxyl. However, othersilicone fluids having skin conditioning properties may be used. Thenon-volatile polyalkyl siloxane fluids that may be used include, forexample, polydimethylsiloxanes. These siloxanes are available, forexample, from the General Electric Company as a Viscasil (RTM) seriesand from Dow Corning as the Dow Corning 200 series. Preferably, theviscosity ranges' from about 10 mm².s⁻¹ to about 100,000 mm².s⁻¹ at 25°C. The polyalkylaryl siloxane fluids that may be used, also include, forexample, polymethylphenylsiloxanes. These siloxanes are available, forexample, from the General Electric Company as SF 1075 methyl phenylfluid or from Dow Corning as 556 Cosmetic Grade Fluid. The polyethersiloxane copolymer that may be used includes, for example, apolypropylene oxide modified dimethylpolysiloxane (e.g., Dow CorningDC-1248) although ethylene oxide or mixtures of ethylene oxide andpropylene oxide may also be used.

References disclosing suitable silicone fluids include U.S. Pat. No.2,826,551, Green; U.S. Pat. No. 3,964,500, Drakoff, issued Jun. 22,1976; U.S. Pat. No. 4,364,837, Pader; and GB-A-849,433, Woolston. Inaddition, Silicone Compounds distributed by Petrarch Systems Inc., 1984provides an extensive (though not exclusive) listing of suitablesilicone fluids.

Preferred non-volatile silicones for use herein includepolydiorganosiloxane-polyoxyalkylene copolymers containing at least onepolydiorganosiloxane segment and at least one polyoxyalkylene segment,said polydiorganosiloxane segment consisting essentially of

    R.sub.b SiO.sup.(4-b)/2

siloxane units wherein b has a value of from about 0 to about 3,inclusive, there being an average value of approximately 2 R radicalsper silicon for all siloxane units in the copolymer, and R denotes aradical selected from methyl, ethyl, vinyl, phenyl and a divalentradical bonding said polyoxyalkylene segment to the polydiorganosiloxanesegment, at least about 95% of all R radicals being methyl; and saidpolyoxyalkylene segment having an average molecular weight of at leastabout 1000 and consisting of from about 0 to about 50 mol percentpolyoxypropylene units and from about 50 to about 100 mol percentpolyoxyethylene units, at least one terminal portion of saidpolyoxyalkylene segment being bonded to said polydiorganosiloxanesegment, any terminal portion of said polyoxyalkylene segment not bondedto said polydiorganosiloxane segment being satisfied by a terminatingradical; the weight ratio of polydiorganosiloxane segments topolyoxyalkylene segments in said copolymer having a value of from about2 to about 8. Such polymers are described in U.S. Pat. No. 4,268,499.

More preferred for use herein are polydiorganosiloxane-polyoxyalkylenecopolymers having the general formula: ##STR2## wherein x and y areselected such that the weight ratio of polydiorganosiloxane segments topolyoxalkylene segments is from about 2 to about 8, the mol ratio ofa:(a+b) is from about 0.5 to about 1, and R is a chain terminatinggroup, especially selected from hydrogen; hydroxyl; alkyl, such asmethyl, ethyl, propyl, butyl, benzyl; aryl, such as phenyl; alkoxy suchas methoxy, ethoxy, propoxy, butoxy; benzyloxy; aryloxy, such asphenoxy; alkenyloxy, such as vinyloxy and allyloxy; acyloxy, such asacetoxy, acryloxy and propionoxy and amino, such as dimethylamino.

The number of and average molecular weights of the segments in thecopolymer are such that the weight ratio of polydiorganosiloxanesegments to polyoxyalkylene segments in the copolymer is preferably fromabout 2.5 to about 4.0.

Suitable copolymers are available commercially under the tradenamesBelsil (RTM) from Wacker-Chemie GmbH, Geschaftsbereich S, Postfach'D-8000 Munich 22 and Abil (RTM) from Th. Goldschmidt Ltd,. Tego House,Victoria Road, Ruislip, Middlesex, HA4 OYL. Particularly preferred foruse herein are Belsil (RTM) 6031, Abil (RTM) B88183 and DC3225C. Apreferred silicone herein is known by its CTFA designation asdimethicone copolyol.

The silicone oil phase preferably comprises from about 2% to about 25%,more preferably from about 5% to about 15% by weight of composition ofnon-volatile silicones.

A highly preferred component of the compositions herein is a humectantor mixture of humectants. The humectant or mixture of humectants hereinis present in an amount of from about 0.1% to about 30% preferably fromabout 5% to about 25%, and more preferably from about 10% to about 20%by weight of composition. The humectant or mixture of humectants ispreferably present in one or more of the aqueous phases.

The humectant can be incorporated at least partly into the oil phase ofthe water-in-oil emulsion so as to form a multiphasehumectant-in-oil-in-water dispersion. The oil phase can comprise fromabout 0.1% to about 10%, more preferably from about 0.1% to about 3% byweight of humectant on a composition basis. The humectant can beintroduced into the oil phase in the form of a mixture with orincorporated within a particulate lipophilic or hydrophobic carriermaterial.

Suitable humectants include sorbitol, panthenols, propylene glycol,butylene glycol, hexylene glycol, alkoxylated glucose derivatives, suchas Glucam (RTM) E-20, hexanetriol, and glucose ethers, and mixturesthereof. Urea is also suitably added as a humectant in one or more ofthe internal aqueous phases.

The panthenol moisturiser can be selected from D-panthenol([R]-2,4-dihydroxy-N-[3-hydroxypropyl)]-3,3-dimethylbutamide),DL-panthenol, calcium pantothenate, royal jelly, panthetine,pantotheine, panthenyl ethyl ether, pangamic acid, pyridoxin, pantoyllactose and Vitamin B complex.

The preferred humectant herein is glycerine. Chemically, glycerine is1,2,3-propanetriol and is a product of commerce.

Preferred embodiments herein comprise a pigment or mixture of pigments.Suitable pigments for use herein can be inorganic and/or organic. Alsoincluded within the term pigment are materials having a low colour orlustre such as matte finishing agents, and also light scattering agents.Examples of suitable pigments are iron oxides, acylglutamate ironoxides, ultramarine blue, D&C dyes, carmine, and mixtures thereof.

The composition of the invention can also include at least one mattefinishing agent. The function of the matte finishing agent is to hideskin defects and reduce shine. Such cosmetically acceptable inorganicagents, i.e., those included in the CTFA Cosmetic Ingredient Dictionary,Third Ed., as silica, hydrated silica, silicone-treated silica beads,mica, talc, polyethylene, titanium dioxide, bentonite, hectorite,kaolin, chalk, diatomaceous earth, zinc oxide (USP or ultrafine) and thelike may be utilized. Of particular usefulness as a matte finishingagent is low lustre pigment such as titanated mica (mica coated withtitanium dioxide) coated with barium sulfate. Of the inorganiccomponents useful as a matte finishing agent low lustre pigment, talc,polyethylene, hydrated silica, kaolin, titanium dioxide and mixturesthereof are particularly preferred.

Materials suitable for use herein as light-scattering agents can begenerally described as spherical shaped inorganic materials having aparticle size of up to about 100 microns, preferably from about 5 toabout 50 microns, for example spherical silica particles.

The total concentration of the pigment may be from about 0.1 to about25% by weight and is preferably from about 1 to about 10% by weight ofthe total composition, the exact concentration being dependent to someextent upon the specific mixture of pigments selected to achieve thedesired shades. The preferred compositions contain from about 2% toabout 20% by weight of titanium dioxide and most preferably from about5% to about 10% by weight of titanium dioxide.

The preferred pigments for use herein from the viewpoint ofmoisturisation, skin feel, skin appearance and emulsion compatibilityare treated pigments. The pigments can be treated with compounds such asamino acids such as lysine, silicones, lauroyl, collagen, polyethylene,lecithin and ester oils. The more preferred pigments are the silicone(polysiloxane) treated pigments.

In preferred embodiments of the invention the water is present in twodiscrete internal aqueous phases, the anti-acne active only beingpresent in one of the aqueous phases. This is particularly beneficialfrom the viewpoint of being able to provide a stable composition havinga high water level without precipitation of the anti-acne active out ofsolution.

The compositions of the present invention can also comprise aparticulate cross-linked hydrophobic acrylate or methacrylate copolymer.This copolymer is particularly valuable for reducing shine andcontrolling oil while helping to provide effective moisturizationbenefits. The cross-linked hydrophobic polymer is preferably in the formof a copolymer lattice with at least one active ingredient disperseduniformly throughout and entrapped within the copolymer lattice.Alternatively, the hydrophobic polymer can take the form of a porousparticle having a surface area (N₂ -BET) in the range from about 50 to500, preferably 100 to 300 m² /g and having the active ingredientabsorbed therein.

The cross-linked hydrophobic polymer when used herein is in an amount offrom about 0.1% to about 10% by weight and is preferably incorporated inthe external silicone-containing oil phase. The active ingredient can beone or more or a mixture of skin compatible oils, skin compatiblehumectants, emollients, moisturizing agents and sunscreens. The polymermaterial is in the form of a powder, the powder being a combined systemof particles. The system of powder particles forms a lattice whichincludes unit particles of less than about one micron in averagediameter, agglomerates of fused unit particles of sized in the range ofabout 20 to 100 microns in average diameter and aggregates of clustersof fused agglomerates of sizes in the range of about 200 to 1,200microns in average diameter.

The powder material of the present invention which can be employed asthe carrier for the active ingredient can be broadly described as across-linked "post absorbed" hydrophobic polymer lattice. The powderpreferably has entrapped and dispersed therein, an active which may bein the form of a solid, liquid or gas. The lattice is in particulateform and constitutes free flowing discrete solid particles when loadedwith the active material. The lattice may contain a predeterminedquantity of the active material. The polymer has the structural formula:##STR3## where the ratio of x to y is 80:20, R' is --CH₂ CH₂ -- and R"is --(CH₂)₁₁ CH₃.

The hydrophobic polymer is a highly crosslinked polymer, moreparticularly a highly cross-linked polymethacrylate copolymer. Thematerial is manufactured by the Dow Corning Corporation, Midland. Mich.,USA, and sold under the trademark POLYTRAP (RTM). It is an ultralightfree-flowing white powder and the particles are capable of absorbinghigh levels of lipophilic liquids and some hydrophilic liquids while atthe same time maintaining a free-flowing powder character. The powderstructure consists of a lattice of unit particles less than one micronthat are fused into agglomerates of 20 to 100 microns and theagglomerates are loosely clustered into macro-particles or aggregates ofabout 200 to about 1200 micron size. The polymer powder is capable ofcontaining as much as four times its weight of fluids, emulsions,dispersions or melted solids.

Adsorption of actives onto the polymer powder can be accomplished usinga stainless steel mixing bowl and a spoon, wherein the active is addedto the powder and the spoon is used to gently fold the active into thepolymer powder. Low viscosity fluids may be adsorbed by addition of thefluids to a sealable vessel containing the polymer and then tumbling thematerials until a consistency is achieved. More elaborate blendingequipment such as ribbon or twin cone blenders can also be employed. Thepreferred active ingredient for use herein is glycerine. Preferably, theweight ratio of humectant:carrier is from about 1:4 to about 3:1.

Also suitable as a highly cross-linked polymethacrylate copolymer isMicrosponges 5647. This takes the form of generally spherical particlesof cross-linked hydrophobic polymer having a pore size of from about0.01 to about 0.05μm and a surface area of 200-300 m² /g. Again, it ispreferably loaded with humectant in the levels described above.

The compositions of the invention can also contain a hydrophilic gellingagent at a level preferably from about 0.01% to about 10%, morepreferably from about 0.02% to about 2%, and especially from about 0.02%to about 0.5%. The gelling agent preferably has a viscosity (1% aqueoussolution, 20° C., Brookfield RVT) of at least about 4000 mPa.s, morepreferably at least about 10,000 mPa.s and especially at least 50,000mPa.s.

Suitable hydrophilic gelling agents can generally be described aswater-soluble or colloidally water-soluble polymers, and includecellulose ethers (e.g. hydroxyethyl cellulose, methyl cellulose,hydroxypropylmethyl cellulose), polyvinylalcohol, polyquaternium-10,guar gum, hydroxypropyl guar gum and xanthan gum.

Other suitable gelling agents suitable for use herein are oleogels suchas trihydroxystearin and aluminium magnesium hydroxy stearate. Thegelling agents herein are particularly valuable for providing excellentstability characteristics over both normal and elevated temperatures.

The compositions herein can additionally comprise an emollient.Emollients suitable for the compositions of the present inventioninclude natural and synthetic oils selected from mineral, vegetable, andanimal oils, fats and waxes, fatty acid esters, fatty alcohols, alkyleneglycol and polyalkylene glycol ethers and esters, fatty acids andmixtures thereof.

Suitable emollients for use herein include, for example, optionallyhydroxy-substituted C₈ -C₅₀ unsaturated fatty acids and esters thereof,C₁ -C₂₄ esters of C₈ -C₃₀ saturated fatty acids such as isopropylmyristate, cetyl palmitate and octyldodecylmyristate (Wickenol 142),beeswax, saturated and unsaturated fatty alcohols such as behenylalcohol and cetyl alcohol, hydrocarbons such as mineral oils, petrolatumand squalane, fatty sorbitan esters (see U.S. Pat. No. 3,988,255,Seiden, issued Oct. 26, 1976), lanolin and lanolin derivatives, such aslanolin alcohol ethoxylated, hydroxylated and acetylated lanolins,cholesterol and derivatives thereof, animal and vegetable triglyceridessuch as almond oil, peanut oil, wheat germ oil, linseed oil, jojoba oil,oil of apricot pits, walnuts, palm nuts, pistachio nuts, sesame seeds,rapeseed, cade oil, corn oil, peach pit oil, poppyseed oil, pine oil,castor oil, soybean oil, avocado oil, safflower oil, coconut oil,hazelnut oil, olive oil, grapeseed oil, and sunflower seed oil and C₁-C₂₄ esters of dimer and trimer acids such as diisopropyl dimerate,diisostearylmalate, diisostearyldimerate and triisostearyltrimerate.

Preferred emollients are selected from hydrocarbons such asisohexadecane, mineral oils, petrolatum and squalane, lanolin alcohol,and stearyl alcohol. These emollients may be used independently or inmixtures and may be present in the composition of the present inventionin an amount from about 1% to about 30% by weight, and preferably arepresent in an amount from about 5% to about 15% by weight of the totalcomposition.

The composition may also contain additional materials such as, forexample, fragrances, fillers such as nylon, sun-screens, preservatives,proteins, antioxidants, chelating agents and water-in-oil emulsifiers asappropriate.

Another optional component of the make-up composition is one or moreultraviolet absorbing agents. Ultraviolet absorbing agents, oftendescribed as sunscreening agents, can be present in a concentration inthe range of between about 1% and about 12% by weight, based on thetotal weight of composition. Preferably, the UV absorbing agentsconstitute between about 2% and 8% by weight. More preferably, the UVabsorbing agents can be present in the composition in a concentrationrange of between about 4% and about 6% by weight. Of the ultravioletabsorbing agents suitable for use herein, benzophenone-3, octyl dimethylPABA (Padimate 0) and mixtures thereof are particularly preferred.

Another optional but preferred component herein is one or moreadditional chelating agents, preferably in the range of from about 0.02%to about 0.10% by weight, based on the total weight of the composition.Preferably, the chelating agent is present in a concentration in therange of between about 0.03% and about 0.07% by weight, based on thetotal weight of the composition. Among the chelating agents that may beincluded in the composition is tetrasodium EDTA.

Another optional but preferred component of the cosmetic composition isone or more preservatives. The preservative concentration in thefoundation composition, based on the total weight of that composition,is in the range of between about 0.05% and about 0.8% by weight,preferably between about 0.1% and about 0.3% by weight. Suitablepreservatives for use herein include sodium benzoate and propyl paraben,and mixtures thereof.

The cosmetic compositions of the present invention can be in the form ofmoisturising creams, lotions or gels, and pigmented compositions such astinted moisturisers, foundation and liquid concealers.

The following Table is provided to illustrate compositions of thepresent invention:

    ______________________________________                                                    I      II     III  IV   V    VI   VII                                Wt Wt Wt Wt Wt Wt Wt                                                         Example % % % % % % %                                                       ______________________________________                                        A.                                                                              Cetyloctanoate 1.00 0.0 0.0 0.0 0.0 0.0 2.0                                   Cyclomethicone 8.57 8.0 8.3 9.0 12.0 8.57 8.57                                Cyclomethicone/ 12.00 12.5 11.5 12.1 12.3 11.00 12.1                          dimethicone                                                                   copolyol (90:10)                                                              Propylparaben 0.75 0.75 0.0 0.75 0.0 0.75 0.75                                (33%) in laureth-7                                                            Dimethicone Fluid 0.0 0.0 2.0 0.0 0.0 0.0 0.0                                 Benzophenene-3 0.0 0.0 0.0 0.0 0.0 2.0 0.0                                    Propylene glycol 0.0 0.0 0.0 4.0 0.0 5.0 0.0                                  Dicaprylate/                                                                  Dicaprate                                                                     Isopropyl Palmitate 3.0 0.0 3.0 0.0 4.0 0.0 0.0                               B.                                                                            Titanium Dioxide 2.0 2.0 2.5 2.0 3.0 3.5 2.6                                  (silicone treated)                                                            Titanium Dioxide 2.0 2.0 1.0 1.5 1.8 2.1 1.0                                  treated (Aluminium                                                            hydrate, stearic                                                              acid)                                                                         Titanated Micas 0.1 0.0 0.0 0.0 0.0 0.0 0.1                                   Talc 3.38 4.5 5.0 0.7 0.7 0.7 3.38                                            Silica 0.6 0.0 0.0 0.0 0.6 0.0 0.0                                            Nylon 0.0 0.0 0.0 0.0 0.5 0.0 0.0                                             Zinc Oxide 2.0 2.0 1.0 2.0 2.0 2.0 2.0                                        (Microfine)                                                                   C.                                                                            Cyclomethicone/ 0.5 0.5 0.5 0.5 0.5 0.5 0.5                                   D.                                                                            Yellow Iron Oxide 0.5 0.6 0.52 0.53 0.61 0.54 0.5                             Red Iron Oxide 0.28 0.3 0.31 0.25 0.27 0.2 0.3                                Black Iron Oxide 0.05 0.1 0.07 0.05 0.06 0.07 0.1                             E.                                                                            Synthetic Wax 0.1 0.5 0.5 0.1 0.0 0.0 0.0                                     Arachidyl behenate 0.3 0.0 0.0 0.3 0.5 0.3 0.3                                Stearic Acid 0.0 0.0 0.0 0.0 0.0 0.0 2.5                                      Palmitic Acid 0.0 0.0 0.0 0.0 0.0 2.5 0.0                                     Silica 0.1 0.0 0.1 0.0 0.1 0.0 0.1                                            (Spheron P1500)                                                               F.                                                                            Trihydroxy-stearin 0.3 0.3 0.5 0.6 0.0 0.0 0.0                                Cyclomethicone 1.0 1.0 0.0 0.0 1.0 1.0 1.0                                    Beeswax 1.5 1.2 0.0 0.0 1.3 0.0 0.0                                           Abil WED9 0.0 3.0 0.0 0.0 0.0 0.0 0.0                                         G.                                                                            Ethylene brassylate 0.05 0.0 0.0 0.0 0.0 0.05 0.05                            BHT 0.05 0.0 0.0 0.0 0.0 0.05 0.05                                            H.                                                                            Deionized water 7.55 7.6 7.7 7.65 7.6 7.4 7.63                                Ethanol 4.0 5.5 4.0 8.0 4.5 5.0 4.0                                           Salicylic acid 1 1 1 2 2 2 0.0                                                Azeleic acid 0.0 0.0 0.0 0.0 0.0 0.0 5                                        Dipropylene glycol 6.0 5.0 6.5 7.00 8.0 6.0 5.0                               Polyvinylpyrroli- 1 2 1.5 1 1 1 2                                             done (Luviskol K17)                                                           Sodium citrate 0.3 0.3 0.3 0.2 0.4 0.3 0.4                                    I.                                                                            Deionized water 12.0 12.2 11.5 11.8 12.0 12.1 12.2                            Sodium chloride 0.2 0.2 0.2 0.2 0.1 0.2 0.1                                   Tetrasodium EDTA 0.04 0.04 0.04 0.04 0.04 0.04 0.04                           Glycerin 4 4 4 4 4 4 4                                                        J.                                                                          Deionized water                                                                           to 100                                                            Sodium chloride                                                                           0.2    0.3    0.2  0.3  0.3  0.3  0.4                               Polyvinylpyrrolid- 0.5 0.0 0.0 0.6 1.0 0.8 0.0                                one (Luviskol K17)                                                            Tetrasodium EDTA 0.06 0.06 0.06 0.06 0.06 0.06 0.06                           Glycerin 6.0 6.0 6.0 6.0 6.0 6.0 6.0                                          Sodium Citrate 0.1 0.0 0.1 0.2 0.0 0.0 0.0                                    K.                                                                            Deionized Water 0.0 0.0 0.0 0.0 10.0 0.0 0.0                                  L.                                                                            Propylene Glycol 0.0 0.0 0.0 2.0 0.0 0.0 0.0                                  Xanthan Gum 0.0 0.0 0.0 0.08 0.0 0.0 0.0                                      M.                                                                            Essential Oils 0.0 0.0 0.0 0.20 0.0 0.0 0.0                                   Perfume Oil 0.0 0.25 0.0 0.20 0.0 0.0 0.0                                     Vitamin A                                                                     Palmitate 0.0 0.05 0.0 0.0 0.0 0.0 0.0                                        N.                                                                            Aloe Vera Gel 0.0 0.0 3.0 0.0 0.0 0.0 0.0                                     Chamomile Extract 0.0 0.0 0.1 0.0 0.0 0.0 0.0                               ______________________________________                                         *Contains about 1% propylene glycol.                                     

The various components listed in the Table have been segregated intogroups, the constituents of each group being mixed together before beingadded to members of the remaining groups in accordance with theprocedures set forth below.

In the first step, the mixture of components of phase A is stirred forapproximately 5 minutes with sheer mixing until homogeneous. With highspeed sheer mixing, the materials of phase B are added gradually to Aand the batch is mixed for 20 minutes until dispersed.

The components of phase C and then phase D are slowly added to themixture of phases A and B with high shear mixing until dispersed. Silicais added at this point and dispersed through the mixture.

The resulting batch heated to 90° C. before the addition of thecomponents of phase E. The vessel is cooled to 55° C. and the premixedphase F is added. The batch is mixed until homogeneous. The mixture iscooled to 30° C. and phase G is added.

Phase H is prepared by first dissolving the polyvinylpyrrolidonecomplexing agent in alcoholic solvent and then dissolving the anti-acneactive followed by the remaining components, ending with adding asolution of citric acid or salt. Phase I is then added to phase H andthe resulting mixture is added to the oil phase. Premixed phase J isthen also added to the oil phase.

Finally phases K, L, M and N are added as diluent.

The resulting composition is ready for packaging.

The compositions of the Examples exhibit moisturisation, anti-acneactivity, skin anti-ageing benefits, together with improved formulationand colour stability, skin feel and appearance.

We claim:
 1. An anti-acne cosmetic composition in the form of a multiplephase water-in-oil emulsion, wherein the composition comprises:(a) twoor more aqueous phases; and (b) a coalescence inhibitor for preventingcoalescence of the aqueous phases;and wherein at least a first aqueousphase comprises an anti-acne active in the form of an aqueous/alcoholicsolution.
 2. An anti-acne cosmetic composition according to claim 1wherein the coalescence inhibitor is an electrolyte or mixture ofelectrolytes.
 3. An anti-acne cosmetic composition according to claim 2wherein the electrolyte is sodium chloride.
 4. An anti-acne cosmeticcomposition according to claim 1 wherein the coalescence inhibitor ispresent at a level of from about 0.05% to about 5% by weight ofcomposition.
 5. An anti-acne cosmetic composition according to claim 1wherein the coalescence inhibitor is present at a level of from 0.01% toabout 1% by weight of composition.
 6. An anti-acne cosmetic compositionaccording to claim 1 wherein the first aqueous phase comprises no morethan 20% by weight of composition of water.
 7. An anti-acne cosmeticcomposition according to any of claim 1 comprising a second aqueousphase which comprises at least about 15% by weight of composition ofwater.
 8. An anti-acne cosmetic composition according to claim 1comprising in total from about 30% to about 50% by weight of water andfrom about 1% to about 15% by weight of alcoholic solvent, and whereinthe composition comprises anti-acne active in an amount exceeding itssolubility in an equivalent mixture of water and solvent.
 9. Ananti-acne cosmetic composition according to claim 1 wherein theanti-acne active is selected from salicylic acid, retinoic acid, azelaicacid, lactic acid, glycolic acid, pyruvic acid, flavonoids, andderivatives and mixtures thereof.
 10. An anti-acne cosmetic compositionaccording to claims 9 comprising from about 0.1% to about 10% by weightof the anti-acne active.
 11. An anti-acne cosmetic composition accordingto any of claims 1 comprising from about 1% to about 50% by weight ofsilicone oil selected from volatile silicones, non-volatile siliconesand mixtures thereof.
 12. An anti-acne cosmetic composition according toclaim 11 wherein the volatile silicone oil is selected from cyclicpolyorganicsiloxanes having viscosities less than about 10 centistokesand linear polyorganosiloxanes having viscosities of less than about 5centistokes at 25° C., and mixtures thereof.
 13. An anti-acne cosmeticcomposition according to claim 12 wherein the volatile silicone oil isselected from cyclic polydimethylsiloxanes containing from about 3 toabout 9 silicon atoms and linear polydimethylsiloxanes containing fromabout 3 to about 9 silicon atoms.
 14. An anti-acne cosmetic compositionsaccording to claim 13 wherein the non-volatile silicone oil comprises apolydiorganosiloxane-polyoxyalkylene copolymer containing at least onepolydiorganosiloxane segment and at least one polyoxyalkylene segment.15. An anti-acne cosmetic composition according to claim 14 wherein thepolydiorganosiloxane-polyoxyalkylene copolymer is dimethicone copolyol.16. An anti-acne cosmetic composition according to claim 1 additionallycomprising from about 0.1% to about 30% by weight of humectant.
 17. Ananti-acne cosmetic composition according to claim 16 wherein thehumectant is glycerin.
 18. An anti-acne cosmetic composition accordingto claim 1 comprising from about 0.01% to about 10% by weight of pigmentor mixture of pigments.
 19. An anti-acne cosmetic composition accordingto claim 10 wherein the anti-acne active is salicylic acid.
 20. Ananti-acne cosmetic composition according to claim 1 additionallycomprising from about 0.1% to about 10% by weight ofpolyvinylpyrrolidone complexing agent.
 21. An anti-acne cosmeticcomposition according to claim 1 additionally comprising from about0.01% to about 5% by weight of citric acid or salt thereof.
 22. Ananti-acne cosmetic composition according to claim 21 wherein thesilicone oil comprises from about 2% to about 25% by weight ofcompositions of non-volatile silicones.
 23. An anti-acne cosmeticcomposition according to claim 1 additonally comprising from about 1% toabout 15% by weight of an emollient which is a natural or synthetic oilselected from mineral, vegetable and animal oils, fats and waxes, fattyacid esters, fatty alcohols, alkylene glycol and polyalkylene glycolethers and esters, fatty acids and mixtures thereof.
 24. An anti-acnecosmetic composition according to claim 23 wherein the emollient isselected from isopropylpalmitate, isopropyl isostearate, dioctylmaleate, propylene glycol dicaprylate/propylene glycol dicaprate,caprylic triglyceride/capric triglyceride, squalane, mineral oil,cetearylisononanoate and lanolin alcohol, and mixtures thereof.
 25. Ananti-acne cosmetic composition according to claim 1 wherein theaqueous/alcoholic solution of anti-acne active has a pH of from about 1to about
 7. 26. Process for preparing an anti-acne composition accordingto claim 1, the process comprising the steps of:(a) preparing the firstaqueous phase by dissolving the anti-acne active in an aqueous/alcoholicsolution; (b) admixing the first aqueous phase with the oil phase; and(c) subsequently adding one or more additional aqueous phase or phasesto the resulting mixture to form the multiple phase water-in-oilemulsion, the first and/or additional aqueous phase or phases havingdissolved therein the coalescence inhibitor.
 27. An anti-acne cosmeticcomposition according to claim 13 wherein the volatile silicone oil isselected from cyclic polydimethylsiloxanes containing from about 4 toabout 5 silicon atoms and linear polydimethylsiloxanes containing fromabout 3 to about 9 silicon atoms.
 28. An anti-acne cosmetic compositionaccording to claim 22 wherein the silicone oil comprises from about 5%to about 15% by weight of compositions of non-volatile silicones.
 29. Ananti-acne cosmetic composition according to claim 25 wherein theaqueous/alcoholic solution of anti-acne active has a pH of from about 2to about
 5. 30. An anti-acne cosmetic composition according to claim 29wherein the aqueous/alcoholic solution of anti-acne active has a pH offrom about 2 to about 4.